Radiocondenser



I April 20 1926. 1,581,356

C.LOFBERG RADIOCONDENSER Filed Dec. 16, 1924 INVENTOR cmez/vcz J0F5 5Q6 Patented Apia 20, 1%26.

UITED STTES PAYNE CLARENCE LOFBERG, OF BOGOTA, NEW JERSEY, A$SICTNOB 'IO NELSON TOOL COMPANY INC, OF NEJV YORK, N. Y., A CORPORATION OF NEW YORK.

RADIOCONDENSER.

Application filed December 16, 1824. Serial No. 756,171.

To all whom 2'23 may concern.

Be it known that I, CLARENCE Lornnnc, a citizen of the United States, and a resident of Bogota. in the county of Bergen and State New Jersey, have invented certain new and useful Improvements in Radiocondensers, of which the following is a specification.

My invention relates to variable condensers particularly adapted for use in con junction with radio apparatus and furthermore relates especially to that class of condensers in which the lined and movable electrodes comprise a plurality of metallic plates adapted to be brought into juxtaposition with each other without actual contact whereby the working capacity of the condenser may be varied.

The principal object of the invention is the production of a condenser of the'type specified which shall be of simple construction and of ease of assembly whereby the parts may be readily taken apart for repair.

A further object of the invention is the production of a condenser of the above type with the parts so constructed and operable that the full working capacity thereof may not be obtained until the conventional dial or disc has been rotated through approximately 360 in eontradistinction to other types wherein a rotation of the dial or disc through approximately 180 only is possible. \Vith my construction, therefore, a very much finer variation in the working capacity may be obtained than in other types where the dials or discs in both are rotated through the same number of degrees.

Further objects of the invention are the production of acondenser so constructed as to have a. low dielectric loss, the production of a condenser in which the electrodes are so mounted and supported as to obviate the possibility of injury thereto and a condenser in which slippage of the dial or disc and the consequent variation in the relative position of the electrodes is not possible.

Other and further objects and advantages of the invention will appear from the accompanying description, the invention consisting in the novel condenser hereinafter more particularly described and then specified in the claims.

In the accompanying drawings illustrating a practical embodiment of the invention:

Fig. 1 is a plan view of my improved condenser.

Fig. 2' is a vertical section on the line 22 of Fig. 1.

Fig. 3 is a horizontal section on the line 3-3 of Fig. 1.

Referring in detail to the several figures of the drawing:

1 indicates the rear metallic plate constituting the rear wall of the device while 2 indicates the front metallic plate constituting the front wall which provided with upper and lower inturned ilange integral therewith and indicated at 3 and i respectively. Said flanges are provided with grooves or slots in alignment receiving a slidable plate 6 which is slida-ble therein. The front and rear walls 2 and 1 are held together on one. side and at their upper and lower outer cor ners by the bolts (7 and the nuts 8 which are screwed on the ends thereof and on the other side by the bolts 9 and the nuts 10 screwed on the ends of said bolts. 11 indicates a plurality of metallic plates constituting the fixed electrode of the condenser which are equidistantly spaced apart and which are provided with openings adjacent their upper and lower outer corners to receive the bolts 9. Said plates 11 are spaced apart on said bolts 9 by suitable metallic washers 12 and washers of insulatingmaterial which are indicated at 13 separate the washers l2 and the nuts 10 from the walls 1 and 2.

The slidable plate 6 is provided with upper and lower bolts 1d extending through their upper and lower outer corners as well as through the upper and lower outer cor- 11ers of a plurality of metallic plates 15 constituting the movable electrode of the condenser, said plates being equidistantly spaced apart on said bolts by washers 16 and the parts clamped together by the nuts 17. Said plates are so positioned as to be adapted to move or slide in a rectilinear direction intermediate the plates 11 without contacting therewith.

Mounted on the front wall 2 is a bearing 18 receiving a shaft 19 the outer end of which carries a dial or disc and an operating knob 21. Said dial or disc is provided with markings or gradations (not shown) as is customary in devices of this general character. The inner end of the shaft 19 has a pinion or gear 22 mounted thereon which meshes with a rack 23 one end of which is pivoted, as at 24, to the slidable plate 6. For maintaining the rack and pinion in constant and intimate mesh I provide a leaf spring 25 which is also fastened to the movable plate 6 and the ends of which bear against or engage the lower side of said pivoted rack and tend to urge or force said rack upwardly on its pivot. I also provide a spring 26 which is carried by the shaft 19 and is disposed intermediate the front wall 2 and the pinion 22 and which presses against said pinion and acts to prevent a longitudinal movement of the shaft 19 in its bearing in an obvious manner.

It will be apparent fron'i the foregoing description that a rotation of the knob 21 in a clockwise direction moves or slides the plate 6 in the grooves to the right in a rectilinear direction whereby the plates are brought intermediate the plates ll, the working capacity of the condenser being directly proportional to the degree or extent of. movement of the plates 15. .l hen the full capacity has been reached the dial or disc will have been rotated through 360 which is not possible in analogous devices of which I have knowledge for the reason that the movable plates in those devices must be swung on a pivot to bring them in juxtaposition with the fixed plates.

For the sake o1 brevity I have not shown any of the electrical connections leading to the condenser and they form no part of my invention. It will further be understood that in some cases I propose to eliminate entirely the rear wall 1 as well as the bolts 7 and to have the bolts 9 held or secured to the front wall 2 only.

What I claim as my invention is 1. A condenser comprising a plurality of fixed plates, a slidable member, a plurality of movable plates secured to said slidable member, a rack carried by said slidable member, a pinion meshing with said rack, a shaft on which said pinion is mounted, a spring bearin againstsaid pinion in a direction longitudinally of said shaft and a rotatable member on said shaft whereby upon rotation of said rotatable member said movable plates will be moved intermediate said fixed plates.

2. A condenser comprising a plurality of fixed plates, a slidable member, a plurality of movable plates secured to said slidable member, a rack pivoted to said slidable member, a pinion meshing with said rack, a spring engaging said pivoted rack and urgmg the same into engagement with said pinion and a rotatable member connected to said pinion whereby upon rotation o't said rotatable member said movable plates will be moved intermediate said fixed plates.

3. A condenser comprising a support, inwardly extending flanges on said support provided with grooves therein, a plurality of fixed plates fastened to said support, a slidable member slidable in said grooves, a plurality of movable plates secured to said slidable member, a rack pivoted to said slidable member, a spring secured to said slidable member and engaging said rack to urge the same upwardly on its pivot, a pinion meshing with said rack, a shaft attached to said pinion and extending through said support, a spring intermediate said support and said pinion and bearing against said pinion and a rotatable member on said shat't adapted on rotation thereof to move said movable plates intermediate said fixed plates.

Signed at New York in the county of New York and State of New York this 15th day of December A. D. 1924:.

CLARENCE LOFBERG. 

